devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Michael Lawnick <ml.lawnick-Mmb7MZpHnFY@public.gmane.org>
To: Laurent Pinchart
	<laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>,
	Alexander Sverdlin
	<alexander.sverdlin-OYasijW0DpE@public.gmane.org>
Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
	Lawnick Michael 61283229
	<michael.lawnick-OYasijW0DpE@public.gmane.org>,
	Maxime Ripard
	<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
	Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH] of: i2c: Add DT bindings for idle states to PCA954x mux driver
Date: Mon, 15 Dec 2014 13:08:39 +0100	[thread overview]
Message-ID: <548ECF47.8030307@gmx.de> (raw)
In-Reply-To: <4262366.rJm0Aq2lpm@avalon>

Hi Laurent,

Am 15.12.2014 um 09:40 schrieb Laurent Pinchart:
> Hi Alexander,
>
> Thank you for the patch.
>
> On Monday 15 December 2014 02:25:18 Alexander Sverdlin wrote:
>> of: i2c: Add DT bindings for idle states to PCA954x mux driver
>>
>> Introduce two new device tree bindings to specify idle state of PCA954x
>> family of I2C multiplexors:
>>    - idle-state: specifies particular child bus to be selected in idle;
>>    - idle-disconnect: signals that mux should disconnect all child buses in
>> idle;
>
> Could you please briefly explain your use case(s) for those two properties ?

Rationale (which should be added) is:
If there are two or more multiplexers/switches connected to same bus 
unused ones need to be set to neutral/unconnected state, otherwise 
transactions to devices behind current multiplexer get visible to all 
buses lately addressed on the other multiplexers. This will lead to 
address conflicts for all devices with same address.

Usage of new bindings is xor.

KR
Michael

  reply	other threads:[~2014-12-15 12:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-15  1:25 [PATCH] of: i2c: Add DT bindings for idle states to PCA954x mux driver Alexander Sverdlin
     [not found] ` <548E387E.2020502-OYasijW0DpE@public.gmane.org>
2014-12-15  8:40   ` Laurent Pinchart
2014-12-15 12:08     ` Michael Lawnick [this message]
2014-12-16  8:09     ` Alexander Sverdlin
     [not found]       ` <548FE8B2.9010400-OYasijW0DpE@public.gmane.org>
2014-12-16 11:07         ` Laurent Pinchart
2014-12-16 12:49           ` Alexander Sverdlin
     [not found]             ` <54902A49.7030804-OYasijW0DpE@public.gmane.org>
2014-12-16 13:38               ` Laurent Pinchart
2014-12-16 20:13                 ` Alexander Sverdlin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=548ECF47.8030307@gmx.de \
    --to=ml.lawnick-mmb7mzphnfy@public.gmane.org \
    --cc=alexander.sverdlin-OYasijW0DpE@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
    --cc=khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org \
    --cc=laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org \
    --cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org \
    --cc=michael.lawnick-OYasijW0DpE@public.gmane.org \
    --cc=robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).